1. Field of the Invention
The present invention relates to a lens device.
2. Description of the Related Art
There are many lens devices in which a built-in lens is movable in the direction of an optical axis for the change of magnification, the adjustment of a focus, and the like. In a case in which a lens is moved in the direction of an optical axis by a stepping motor, the position of the lens is detected on the basis of the number of pulses. Accordingly, there is a lens device in which a magnet is provided on the outer peripheral surface of a lens holder, a hall IC is provided on the outer peripheral surface of a lens barrel, and the initial position of a lens is detected through the detection of the magnetic flux of the magnet that is performed by the hall IC (JP1993-196853A (JP-H05-196853A)). There are a lens device that detects the position of a lens by using a resistor substrate other than a hall IC (JP2011-33811A), lens devices that detect the position of a lens by using magnetism (JP2006-178085A, JP2000-266984A, and JP2010-139761A), and a lens device that detects the position of a lens by using a photo-interrupter (JP2005-242256A).